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Re: [RDFa, ALL] Ranges of Dublin Core properties and RDFa

From: Ben Adida <ben@adida.net>
Date: Tue, 27 Feb 2007 10:41:01 -0500
Message-ID: <45E4510D.5020503@adida.net>
To: Thomas Baker <baker@sub.uni-goettingen.de>
CC: SWD Working Group <public-swd-wg@w3.org>


Thanks for pointing this out.

We were told by multiple folks that it didn't make sense to have
dc:creator point to a string, e.g. "Mark Birbeck." That's why we added
this comment in the Primer, so we could dodge the issue a bit while
presenting RDFa.

I'm not sure we have any specific feedback for DCMI: we can handle
either case, especially with the striping approach. We just didn't want
to get into striping in the first example.


Thomas Baker wrote:
> Ben, Mark, Michael,
> In Section 3.2, the Primer [1] says:
>     In the above markup and triples, as well as in the rest of
>     the document, we slightly abuse the dc:creator  predicate,
>     which is most often meant to refer to a person, not just
>     a literal. 
> Currently, dc:creator has no formal range, but DCMI is
> considering a proposal to replicate the fifteen properties
> of the http://purl.org/dc/elements/1.1/ namespace into the
> http://purl.org/dc/terms/ namespace and assign ranges 
> to these properties.  This proposal has been out for Public
> Comment, which closes on March 5 (details below).
> Assigning a range to dcterms:creator (proposed range: Agent) would
> in no way break the examples in the Primer, which use dc:creator
> (range undefined).  However, DCMI would encourage new implementations
> of DC metadata to make use of the new dcterms: properties rather than
> the older dc: properties.  Furthermore, as already discussed in the 
> Public Comment period, the proposal to assign ranges
> raises more general issues about the expected ranges of properties such
> as dc:date and dc:creator [2,3].  It would be extremely if this 
> group could provide input to DCMI on this issue - both in general and from
> the standpoint of RDFa (for example, on the assumptions or preferences
> reflected in the quote above).
> Note that a number of other related specifications (especially
> [4], Expressing Dublin Core metadata using RDF) are in the pipeline and 
> depend for their finalization on the outcome of Public Comment on the 
> Abstract Model.
> Tom
> [1] http://www.w3.org/2006/07/SWD/RDFa/primer/
> [2] http://www.jiscmail.ac.uk/cgi-bin/webadmin?A2=ind0702&L=dc-architecture&P=4038
> [3] http://www.jiscmail.ac.uk/cgi-bin/webadmin?A2=ind0702&L=dc-architecture&P=10112
> [4] http://dublincore.org/documents/dc-rdf/
> ----
> I would like to draw the attention of this group to a Public
> Comment period, through 5 March, on a revised version of the
> DCMI Abstract Model [1] and a proposed vocabulary of domains
> and ranges for DCMI metadata terms [2].  
> In particular Section 5, which specifies the relationship
> of the DCMI Abstract Model to RDF [6], may be of interest.
> Further context about this comment period is provided in
> postings to the DC-ARCHITECTURE working group [3,4, see also
> below], where any comments should be posted and discussion
> is now taking place [5].
> Tom Baker
> [1] http://dublincore.org/documents/2007/02/05/abstract-model/
> [2] http://dublincore.org/documents/2007/02/05/domain-range/
> [3] http://www.jiscmail.ac.uk/cgi-bin/webadmin?A2=ind0702&L=dc-architecture&P=171
> [4] http://www.jiscmail.ac.uk/cgi-bin/webadmin?A2=ind0702&L=dc-architecture&P=291
> [5] http://www.jiscmail.ac.uk/lists/dc-architecture.html
> [6] http://dublincore.org/documents/2007/02/05/abstract-model/#sect-5
>> Date: Mon, 5 Feb 2007 18:32:28 +0100
>> From: Thomas Baker <tbaker@tbaker.de>
>> To: DCMI Architecture <dc-architecture@jiscmail.ac.uk>
>> Subject: Public comment for revision of DCMI Abstract Model
>> The DCMI Abstract Model, which attained the status of DCMI
>> Recommendation in March 2005, has been revised in light of
>> discussion and feedback from the DCMI Architecture Working
>> Group, the DCMI Usage Board, and the broader community.
>> This revised version of the Abstract Model [1] has been
>> posted for a four-week public comment period.  The major
>> differences between this revised version and the 2005 version
>> [2] are summarized below.  A revised DCMI Namespace Policy
>> [3] proposing a new DCMI namespace for Abstract Model entities
>> has been posted for comment at the same time.
>> Interested members of the public are invited to post comments
>> on these Proposed Recommendations to the DC-ARCHITECTURE
>> mailing list [4], including "[DCAM Public Comment]" in the
>> subject line. Public Comment will be open from 5 February
>> through 5 March 2007.
>> [1] http://dublincore.org/documents/2007/02/05/abstract-model/
>> [2] http://dublincore.org/documents/2005/03/07/abstract-model/
>> [3] http://dublincore.org/documents/2007/02/05/dcmi-namespace/
>> [4] http://www.jiscmail.ac.uk/lists/dc-architecture.html
>> Changes in the DCMI Abstract Model, 2005 to 2007
>> --  Added a table explicitly mapping Abstract Model entities to
>>     properties and classes of the Resource Description Framework
>>     (RDF) and RDF Schema (RDFS).  The DCMI Abstract Model defines
>>     a particular Description Model on the basis of RDFS semantics.
>> --  Added a separate Vocabulary Model specifying the types
>>     of "terms" used in Dublin Core metadata descriptions and
>>     including support for formal domains and ranges for properties.
>>     The declaration of a vocabulary of classes and their use
>>     as domains and ranges for DCMI properties is the focus of a
>>     separate Public Comment period.
>> --  Changed the definition of 'vocabulary encoding scheme' --
>>     defined in 2005 as "a class that indicates that the value of a
>>     property is taken from a controlled vocabulary" -- to mean "an
>>     enumerated set of resources" of which the value is a member.
>>     (A value can be described as an instance of a class by other
>>     means, such as by a separate statement to this effect).
>> --  Updated the definition of 'rich representation', adding
>>     the notion of 'media type'.
>> Other editorial changes
>> --  Tightened the definition of 'syntax encoding scheme',
>>     explicitly mapping the concept to the RDF Schema class
>>     'Datatype'.
>> --  Tightened terminology and wordings to clarify meaning
>>     (e.g., by consistently using phrases instead of sentences for
>>     definitions; by referring to 'described resource' instead of
>>     just 'resource'; by using the phrase "separate 'description'
>>     about the 'value'" instead of a modeling entity for 'separate
>>     description').
>> --  Shortened the document by removing sections describing
>>     related issues such as 'dumb-down' (formerly Section 5),
>>     'structured values' (formerly Appendix A), and specific
>>     encoding guidelines (formerly Appendixes B, C, and D).
>>     Much of this material will be provided in revised form in
>>     more user-oriented documentation.
>> --  Added a table mapping current Abstract Model terminology
>>     to the terminology in legacy DCMI "grammatical principles"
>>     documentation (now Appendix A).
>> --  Permitted a value string to be associated with either
>>     a language tag or syntax encoding scheme, or neither, but
>>     not both.
>> --  Added a note to the effect that classes can be declared
>>     explicitly or inferred from the domains and ranges of
>>     properties.  Dropped the guideline that in DCMI metadata
>>     descriptions, the class of the resource being described should
>>     be indicated by the value of the Dublin Core Type property.
>> --  Simplified the Description Model, removing 'marked-up
>>     text' and 'structured value string' as separate entities and
>>     rearranging the diagram to improve readability.
>> --  Added placeholder URIs identifying DCMI Abstract Model
>>     entities in a new DCMI namespace (as described in the 
>>     revised DCMI Namespace Policy, also posted for Public
>>     Comment).
>> --  Replaced QNames throughout the document with full URIs.
>> -- 
>> Dr. Thomas Baker <tbaker@tbaker.de>
>> Director, Specifications and Documentation
>> Dublin Core Metadata Initiative
Received on Tuesday, 27 February 2007 15:40:37 GMT

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